package com.mydesign.demo.util;

public class DistanceUtil {
    private static double EARTH_RADIUS = 6378137;
    public static double  getDistance(String lat1Str, String lng1Str, String lat2Str, String lng2Str) {
        Double lat1 = Double.parseDouble(lat1Str);
        Double lng1 = Double.parseDouble(lng1Str);
        Double lat2 = Double.parseDouble(lat2Str);
        Double lng2 = Double.parseDouble(lng2Str);

        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) +
                Math.cos(radLat1)*Math.cos(radLat2)*Math.pow(Math.sin(b/2),2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000) / 10000;
        return s;
    }
    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    public static void main(String[] args) {
        double distance = getDistance("33.386260986328125", "120.19330596923828", "33.388113", "120.205431");
        //120.205308,33.388024
        System.out.println(distance);
    }
}
